In the context of mobile communication systems, it has been suggested to introduce point-to-multipoint (PTM) services, see e.g. Technical Specification 3GPP TS 22.146 V5 1.0 (December 2001), which technical specification is herewith incorporated by reference. In this technical specification two basic types of PTM services are described, namely multicast and broadcast. Both multicast and broadcast have in common that a single source transmits data or data units to several destinations. In accordance with the above-mentioned technical specification TS 22.146, the broadcast mode is a unidirectional point-to-multipoint transmission of data from a single source entity to all users in a broadcast area or areas. The multicast mode allows the unidirectional point-to-multipoint transmission of data from a single source point to a multicast group in a multicast area. In other words, in a multicast transmission, data is only sent to the members who have joined the corresponding multicast group, whereas a broadcast transmission can be received by anyone within a predetermined (logical or physical) area.
Regarding charging or billing, the TS 22.146 only mentions that it should be possible to collect charging information for the use of broadcast services and multicast services. However, it is not indicated how this can be done.